Question: Tiffany is 4 times as old as Omar and is also 27 years older than Omar. How old is Omar?
Explanation: We can use the given information to write down two equations that describe the ages of Tiffany and Omar. Let Tiffany's current age be $t$ and Omar's current age be $o$ $t = 4o$ $t = o + 27$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $o$ , and both of our equations have $t$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $4o$ $-$ $ (o + 27)$ which combines the information about $o$ from both of our original equations. Solving for $o$ , we get: $3 o = 27$ $o = 9$.